the eolian deposition piled up on the protrusions, the lacustrine deposition heaped up in the depressions. This geomorphic pattern probably sustained from 7.3Ma B.P.

• 蓝田组和游河组形成时期，研究区地形地貌发生分异，表现为地形凸起和凹陷并存，凸起区堆积风成沉积，凹陷区接受湖泊沉积，这一地貌格局很可能自7.；3Ma B